root_device Profile Keyword (ZFS
and UFS)

root_device cwtxdysz

root_device specifies the
device to be used for the root pool. The root_device keyword
determines where the operating system is installed. This keyword is used the
same in both ZFS and a UFS file system with some limitations. For the ZFS
root pool, the root device is limited to a single system. This keyword is
not useful for mirrored pools.